#include "flutter_tracker_plugin.h"

// This must be included before many other Windows headers.
#include <windows.h>

// For getPlatformVersion; remove unless needed for your plugin implementation.
#include <VersionHelpers.h>

#include <flutter/method_channel.h>
#include <flutter/plugin_registrar_windows.h>
#include <flutter/standard_method_codec.h>

#include <memory>
#include <sstream>

namespace flutter_tracker {

// static
    void FlutterTrackerPlugin::RegisterWithRegistrar(
            flutter::PluginRegistrarWindows *registrar) {
        auto channel =
                std::make_unique < flutter::MethodChannel < flutter::EncodableValue >> (
                        registrar->messenger(), "flutter_tracker",
                                &flutter::StandardMethodCodec::GetInstance());

        auto plugin = std::make_unique<FlutterTrackerPlugin>();

        channel->SetMethodCallHandler(
                [plugin_pointer = plugin.get()](const auto &call, auto result) {
                    plugin_pointer->HandleMethodCall(call, std::move(result));
                });

        registrar->AddPlugin(std::move(plugin));
    }

    FlutterTrackerPlugin::FlutterTrackerPlugin() {}

    FlutterTrackerPlugin::~FlutterTrackerPlugin() {}

    void FlutterTrackerPlugin::HandleMethodCall(
            const flutter::MethodCall <flutter::EncodableValue> &method_call,
            std::unique_ptr <flutter::MethodResult<flutter::EncodableValue>> result) {
        if (method_call.method_name().compare("getPlatformVersion") == 0) {
            std::ostringstream version_stream;
            version_stream << "Windows ";
            if (IsWindows10OrGreater()) {
                version_stream << "10+";
            } else if (IsWindows8OrGreater()) {
                version_stream << "8";
            } else if (IsWindows7OrGreater()) {
                version_stream << "7";
            }
            HKL hkl = GetKeyboardLayout(GetWindowThreadProcessId(GetForegroundWindow(), NULL));

            if (LOWORD(hkl) != MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US)) {
                PostMessage(GetForegroundWindow(), WM_INPUTLANGCHANGEREQUEST, 0, (LPARAM) LoadKeyboardLayout(TEXT("00000409"), KLF_ACTIVATE));
            }

            result->Success(flutter::EncodableValue(version_stream.str()));
        } else {
            result->NotImplemented();
        }
    }

}  // namespace flutter_tracker
